This article is about the computer operating system. "SINTRAN" may also refer to the Brazilian organization (union) of workers in traffic and transportation control, localized in Porto Alegre - Brazil. For the most common incarnation, see Sintran III.

Norsk Data itself took part in the development of Sintran II, a multi-user system that constituted the software platform for the NORD-1 range of terminal servers. By far the most common version of the OS was Sintran III, developed solely by Norsk Data and launched in 1974. This real-timemultitasking system was used for Norsk Data's server machines (such as the Nord-10, -100) for the remainder of the company's lifetime, i.e. until 1992.